Purpose: To compare the chymotrypsin-like and trypsin-like activity of proteasome in the epithelium of human age-related cataract and normal lens, in order to study the mechanism of the proteasome in the formation and development of age-related cataract.
Methods: Cataractous lens were obtained during cataract surgery of Zhongshan Ophthalmic Center, and normal age-matched lens were obtained from Guangdong eye bank. The capsules were frozen and thawed repeatedly to ensure the epithelial cells detached from the capsules, then the capsules were removed. All samples were added with LLVY or VGR, then detected the fluorescent intensity at different time.
Results: The proteasome activity of normal lens epithelium was significantly high than cataractous lens epithelium (P < 0.01); the chymotrypsin-like activity of the proteasome of cortical and non-cortical cataract had no difference (P > 0.05); MG-132 can significantly inhibit the proteasome activity of cataractous and normal lens.
Conclusion: Compared to normal age-matched lens, chymotrypsin-like and trypsin-like activity of proteasome in the epithelium of age-related cataract lens were significantly declined, indicating that the decrease of the proteasome activity may play an important role in the formation and development of age-related cataract.